python/fastapi_startkit: pin to 0.47.0 (FastAPI 0.139) to match baseline

The previous range resolved fastapi-startkit to 0.46.x -> FastAPI 0.124.4,
while the fastapi baseline entry runs FastAPI 0.139. Pin to 0.47.0 so both
Python entries benchmark on the same FastAPI/Starlette (0.139.0 / 1.3.1),
making the comparison apples-to-apples. Idiomatic include_router registration
is kept unchanged. route_spec.rb passes 6/6 on the 0.139 Docker build.

Author: tmgbedu

python/fastapi_startkit/pyproject.toml

@@ -7,4 +7,4 @@ requires = ["flit_core"]
 name = 'server'
 version = '1.0.0'
 description = "Simple benchmark implementation"
-dependencies = ["fastapi-startkit[fastapi]>=0.46,<0.47"]
+dependencies = ["fastapi-startkit[fastapi]==0.47.0"]